Kerfus fell under the textures, and it is impossible to pick it up because of the invisible wall, and also it is broken there, what to do?

try dragging the workbench over to the spot and flipping it over just enough that the crafting box touches kerfus, and then you can disassemble them- the parts should spawn above the floor if the table is completely upside down, save and increase the autosave timer before you do it, but there's a decent chance you have to buy a new one...

not very much chance there, keep trying, and hope you good luck.
id recommend the reddit instead though!